OBJECTIVETo investigate the effects of preconditioning and postconditioning with Shenfu Injection (SFI) on cognitive function in patients after valve replacement under extra-corporeal circulation.

METHODSThirty-two patients prepared to receive valve replacement, aged 25-54 years, with heart function of II-III level, were randomly assigned to four groups, eight in each group. Patients in group E1 received SFI 1 mL/kg after intubation and before blocking the aorta; patients in group E2 received SFI 1 mL/kg after opening the aorta; patients in group E3 received SFI 0.5 mL/kg twice, at before blocking and after opening the aorta, respectively; and patients in group C received 1 mL/kg normal saline after intubation for control. All the medication was infused via pump. Venous blood samples were taken from the internal jugular venous bulb cannula for detecting plasma S100beta protein by ELISA at 6 different time points, i.e. after trachea intubation (T1), 10 min after cardiopulmonary bypass (CPB, T2), hypothermia stabilizing stage (T3), re-warming to 33 degrees C (T4), ending CPB (T5) and 1 h after ending CPB (T6). And patients' cognitive function was assessed for 4 times with mini-mental state examination (MMSE) scale, at the day before operation, and 1, 2, 7 days after operation.

RESULTSThe elevation of S100beta plasma protein was lesser in the three E groups than that in group C (P < 0.05), and the lowest level was shown at T6 in Group E3 (P < 0.05). The highest incidence of cognitive dysfunction occurred in Group C one week after operation (P < 0.05).

CONCLUSIONSFI may reduce the plasma level of S100B protein, maintain stable the structure and function of blood-brain barrier, it is favorable to the post-operational recovery of neurological function of patients, showing good brain protective effect. The optimal effect could be obtained by pump infusion of 0.5 mL/kg of SFI before aortic blocking and after aortic opening.